The present invention relates to a machine unit or installation, consisting of a rotary piston internal combustion engine having a fluid or liquid cooled housing consisting of two side parts and a casing or mantle part with a trochoidal shaped dual-arc raceway or mantle surface. The housing has an eccentric shaft passing therethrough and a triangular piston is journalled upon an eccentric of the eccentric shaft so that corners of the triangular piston move or glide along the raceway or mantle surface in a continuing sliding engagement, whereby the eccentric shaft is connected positively via a belt drive with a refrigeration compressor of the same type of construction as the internal combustion engine.
Such machine units or installations serve predominantly for air conditioning of large capacity vehicles as a consequence of the space-saving manner of construction of the noted machines or engines.